GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: HVAC Schematics

Connector End View Reference: HVAC Connector End Views

DEFINITION: Air does not flow correctly from the air distribution outlets.

1

Did you review the HVAC operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - HVAC Systems - Manual

2

  1. Turn the ignition ON, with the engine OFF.
  2. Place the blower motor switch in the OFF position.

Is the blower motor OFF?

Go to Step 3

Go to Blower Motor Always On

3

Place the blower motor switch in each speed position.

Does the blower motor operate at all?

Go to Step 4

Go to Blower Motor Inoperative

4

Does the blower motor operate correctly for each speed position?

Go to Step 5

Go to Blower Motor Malfunction

5

Is the vehicle equipped with A/C?

Go to Step 6

Go to Step 7

6

  1. Start the engine.
  2. Place the blower motor switch in the maximum speed position.
  3. Lower the glove box off its upper attachments.
  4. Observe the recirculation door.
  5. Place the recirculation switch in the ON position.

Does the recirculation door move to the recirculation position?

Go to Step 7

Go to Air Recirculation Malfunction

7

Inspect the mode door cable and linkage the following conditions:

    • Broken or binding cable, linkage or mode door.
    • An obstruction that prevents the mode door from operating within its full range of motion.
    • Missing seals to the mode door.
    • Misaligned seals to the mode door.

Did you find and correct the condition?

Go to Step 8

Go to High or Low Mode Control Effort in Heating, Ventilation and Air Conditioning

8

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2